These websites below offer experienced hand loaders more research options for powders that provide reduced loads in the .375 Ruger for deer and black bear. I use magnum rifle primers in load development to ensure complete ignition. Carefully work up new loads inspecting each case after firing. I do not advocate the data in these websites but provide them for your information and fun to read articles.

https://www.ballisticstudies.com/Knowledgebase/.375+Ruger.html

I do read that A 5744 works well in the .375 Ruger for reduced loads though I have not loaded or shot it.

375 Ruger Reduced Loads from Chuck Hawkes with A5744 Powder below and grain weight loads.

https://www.chuckhawks.com/reduced_big_bore_loads.htm

IMR 4227 used in Handloader Magazine for 375 Ruger

https://www.handloadermagazine.com/reduced-rifle-loads

Hodgdon Reduced Rifle loads below using the 60% rule with H4895 powder below.

https://hodgdon.com/wp-content/uploads/2016/11/h4895-reduced-rifle-loads.pdf?_ga=2.52837998.715241781.1595099969-1370190430.1595099968

I am lucky to have purchased one of the last cans of SR 4759 powder and am successfully using that for my deer hunting load development for .375 Ruger.

Good Shooting!